The truck driver apparently ignored warning signs when he entered the ancient archaeological site in southern Peru’s desert plains on Saturday night, according to a press release from the country’s Ministry of Culture.

The unauthorized vehicle left “deep tracks” across a 50-meter by 100-meter (164-foot by 328-foot) area of the site, affecting the surface and damaging three of the geoglyphs. The driver, identified by authorities as 40-year-old Jainer Jesus Flores Vigo, was detained that night near the city of Nazca and later released, the ministry said.

The Nazca Lines were etched into the arid ground by the region’s ancient inhabitants approximately 2,000 years ago. They stretch across an area of about 280 square miles, depicting animals, plants, mythical creatures and geometrical figures, according to the United Nations Education, Scientific and Cultural Organization, which declared the area a UNESCO World Heritage Site in 1994.

“They are the most outstanding group of geoglyphs anywhere in the world and are unmatched in its extent, magnitude, quantity, size, diversity and ancient tradition to any similar work in the world,” UNESCO said.

Peru’s Ministry of Culture said it’s working in coordination with Nazca’s prosecutor’s office on the investigation, as authorities pursue charges against the truck driver.

Peru’s Public Ministry had sought nine months of preventive detention and a fine of 5,000 Peruvian soles, or about $1,550, while the investigation continues. But a judge on Tuesday concluded there wasn’t sufficient evidence to indicate the driver acted with intent, according to Peruvian newspaper Peru21.

The Public Ministry subsequently announced that Nazca’s prosecutor was appealing the judge’s decision.